In our previous experiments that were supported by the NIH grant DHHS 1 RO1 AT00493-01 we determined that Millimeter Wave Therapy (MWT) was able to produce hypoalgesia in experimental models of acute and chronic non-neuropathic pain via activation of the system of endogenous opioids. However, it is unclear whether chronic neuropathic pain, that has different neurophysiological mechanisms and is highy resistant to traditional methods of treatment, may be relieved by MWT too. The present study will study and evaluate the ability of MWT to suppress chronic neuropathic pain. Changes in the content of endogenous opioids in the central neural system tissue, as well as the involvement of the various subtypes of opioid receptors, will be of particular interest. Also, different regimens of MWT will be screened in murine model of neuropathic pain in order to define the "optimal" characteristics of the treatment. The effectiveness and type of interaction (synergism or additive effect) in combined treatment with MW and oral ketamine (NMDA receptor blocker) for suppressing the symptoms of experimental neuropathic pain will be dermined as well. Results from the planned project will provide an appropriate scientific base for the introduction of MWT into clinical practice in patients with neuropathic pain conditions.